大型轴类件锻造及热处理工艺对混晶缺陷调控界面的影响  

Influence of forging and heat treatment process on control interface of mixed crystal defect for large shaft parts

作　　者：徐月[1] 刘帅奇 刘建生[1] Xu Yue;Liu Shuaiqi;Liu Jiansheng(College of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《锻压技术》2024年第3期8-17,共10页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51775361);山西省基础研究计划项目(202303021212230);太原科技大学博士启动金(20222055)。

摘　　要：采用拔长和等温热处理实验,探索了超超临界中压转子锻后热处理工艺对终锻成形后混晶控制的工艺容限,发现在混晶缺陷消除方面,锻造与锻后热处理工艺之间的工艺容限为5级混晶度等级。结合有限元模拟与物理模拟实验,以终锻成形后中压转子不产生裂纹为前提,以晶粒尺寸细匀化程度满足锻后热处理工艺容限要求为目的,得到12%Cr转子钢终锻成形时的最佳锻造工艺窗口,即应变速率为0.1 s^(-1)时,始锻温度控制在1140~1275℃、锻比控制在1.157~1.582。基于锻造工艺窗口反推了超超临界中压转子最后一火次成形时各阶梯轴的锻造先后顺序与各轴段锻造时的锻比,结果表明,中压转子各轴段晶粒组织的细匀化程度均能达到实际锻造工艺要求。By drawing and isothermal heat treatment experiments,the process tolerance of post-forging heat treatment process for ultra-supercritical medium-pressure rotor on the control of mixed crystal after final forging was explored,and it was found that the process tolerance between forging process and post-forging heat treatment process was 5-grade mixed crystal degree in eliminating mixed crystal defect.Then,combined with the finite element simulation and physical simulation experiments,for the purpose that the degree of grain size refinement and homogenization of medium-pressure rotor after final forging could meet the process tolerance requirements of post-forging heat treatment process on the premise that the medium-pressure rotor didnot produce cracks after final forging,the optimal forging process window for the final forging of 12%Cr rotor steel was obtained,that is,when the strain rate was O.1 s,the initial forging temperature was controlled at 1140-1275 ℃ and the forging ratio was controlled at 1.157-1.582.Based on the forging process window,the forging sequence and the forging ratio of each stepped shaft during the final forging of ultra-supercritical medium-pressure rotor were deduced.The results show that the degree of grain structure refinement and homogenization for each stepped shaft of medium-pressure rotor can meet the requirements of actual forging process.

关 键 词：超超临界 中压转子 锻后热处理 锻造 混晶 

分 类 号：TG316[金属学及工艺—金属压力加工]